Karen says she relied on her “solutions-oriented” personality and maternal instinct to survive.

When most people do a marathon, they spend months training in advance. Las Vegas mom Karen Klein did one with zero preparation—all to save her family.

Karen walked 26 miles in the snow along a desolate part of the Grand Canyon over 36 hours to seek help after her car got stuck in the mud near the North Rim. Her 10-year-old son and husband were in the car, and Karen decided she would be the one to get help since her husband had recently been in an accident.

"I said, 'I'll go, I'll just walk up to the main road. I'm a runner,'" she told NBC News. Unfortunately, that road is closed to car traffic during the winter. Hours later, she was alone in the dark. So, she kept moving.

Karen hiked 26 miles in the snow with no cell service, no snow boots, and only a small pack of Cheerios for food. "I didn't think I would be out that long," she explained.

At one point, she sought out shelter and wedged herself beneath an evergreen tree. However, she was scared she would fall asleep and freeze to death, so she kept herself awake. “I just talked to myself and rocked back to stay warm," she said. When she got hungry, Karen ate twigs and drank melted snow.

It didn’t end there: After walking for miles, Karen pulled a muscle near her hip and lost a shoe in the snow. To move her leg, she had to physically pick it up and move it forward. "I could only move it 10 steps at a time [before getting] very exhausted and sore,” she said.

Karen finally came across an empty home for park rangers and broke a glass with her elbow to get in. During her ordeal, her husband and son walked in the opposite direction to get cell service to call for help, and a search and rescue team finally discovered Karen at the ranger residence.

Karen says she relied on her “solutions-oriented” personality and maternal instinct to survive. "I can't leave my son without a mom. I'm can't leave my husband without a wife. I'm not letting my parents bury me,” she remembers thinking.

Karen said she knows she’s lucky to be alive, and is currently receiving treatment for frostbitten toes. She may have to have some amputated, but says it’s a “sit-and wait-situation.” However, she’s keeping it all in perspective.

"In the grand scheme of things, I keep thinking: 'You know what? It's a few toes. Don't worry about it,’” she says.